Cromwell, Nathan Bedford Forrest, Scipio Africanus, Alexander the Great, Charles XII of Sweden.
Abraham Lincoln. When elected he had even less executive experience than Obama, and just about the same amount of political experience. Great differences between the two in other areas, but not in their amount of experience.
Scipio Africanus served for years in the legions before taking command of army in Spain. He probably had more combat experience (of actually actively killing) then any modern day general.